Contact members with a bifurcated part formed such that on thrusting transversely against an insulated conductor they penetrate the insulation and make electrical contact with the conductor, so-called slit contact tips, are already known and are used in different connections for connecting conductors with each other in terminal boxes or for connecting conductors with electrical components in circuit boards or the like.
Contact members of the kind mentioned above are stamped out from a flat blank and a slit is stamped in the member. Since it is not possible to stamp out narrower slits at about 0.6 mm, because the punch will break when it is used in production, the slit obtained is still too wide to give sure contact against wires with a conductor diameter of 0.4-0.7 mm. To remedy this, and to obtain a narrow slit such that the contact member cuts through the insulation and gives a gas-tight contact with the conductor, the material lying parallel to the slit in the contact region is stamped. The stamped impression is done with a punch which plastically deforms the edges of the slit towards each other. Above the slit the punch has a shallow upside-down V profile, which is defined by flat or somewhat outwardly curved surfaces substantially parallel to the working direction of the punch. The punch works against a flat die. For reliably controlling the slit width, there have also been attempts to use a die with a tongue that thrusts into the slit. Since the tongue is too small it is easily broken, however.